Maersk Supply Service: subsea support vessel

When Maersk Supply Service and DeepOcean chose Damen Shipyards Galati to build a new subsea support vessel, Damen was delighted that these leading operators had shown such confidence in the company and in the new cable layer design, which embodies years of R&D efforts.

This is the second order for the state-of-the-art Damen Offshore Carrier DOC 8500. The first is owned by Van Oord and is deployed laying cables at offshore wind farms.

There is more and more demand from the offshore industry to transport cables of approximately 7,000 tonnes in one length and the Damen DOC 8500 is able to do this comfortably and safely.

The latest order followed a long-term charter agreement between expanding subsea contractor DeepOcean and Maersk Supply Service, which will be the owner and operator of the new vessel. Both Maersk Supply Service and DeepOcean are new customers to Damen.

The Damen DOC 8500 is designed to meet the high standards demanded by the North Sea oil and gas industry. Damen Sales Manager Remko Bouma who is overseeing the vessel construction, comments: “We really believe in the new design, which provides a stable, basic offshore platform vessel, coupled with a very high cable carrying capacity for the carrousel on top. It is a very flexible concept, the customer can incorporate a large number of purpose-specific demands into the design and therefore utilise the vessel efficiently.”

“There is more and more demand from the offshore industry to transport cables of approximately 7,000 tonnes in one length and the Damen DOC 8500 is able to do this comfortably and safely.”

Optimum cable load
Damen worked very closely with Maersk Supply Service and DeepOcean regarding the specific requirements for the vessel. This next generation cable lay vessel is well suited for installation and burial projects and can use its 7,000 tonne carousel from landfall to deepwater and also in remote geographical locations.The DOC 8500 has been developed as a flexible platform for both transport and installation work offshore. Remko adds: “Its bow and slender hull optimise seakeeping in rough seas and suppress slamming.”

Its high on-deck cable carrying capacity makes it particularly competitive as a cable layer. Maersk Supply Service required it to have the maximum carrying capacity so the vessel was lengthened from the standard DOC 8500 and it has a deeper draught. The result is a vessel with a 138.2 metre length overall, which is 7 to 8 metres longer than the prototype. The vessel has a deadweight of 9,300 tonnes and the vessel features 2,200 m² of unobstructed deck with a 20T/m2 load capacity and a top speed of 12 knots.

The DOC 8500 was also adjusted to carry out shallow draught operations. It was fitted with a 7-point mooring system and has DP2 capabilities for operating in more challenging seas. The vessel, which is fitted with a helideck, also has the ability to take the ground fully loaded and will run on either MGO or HFO.

“We are working very closely with Maersk Supply Service, which is very experienced working with these types of vessels. We have learnt from each other during the engineering phase and it is a very constructive cooperation where the expertise from all three companies is embodied in this new vessel,” says Remko.

On schedule
“Maersk has a lot of experience in operating these vessels and we can bring our technical and construction knowledge. Coupled with this, Maersk has very stringent HSEQ offshore standards. Damen is always seeking to continuously improve in this area and we can learn from each other here too.” Carsten Plougmann Andersen, Chief Executive Officer of Maersk Supply Service, said at the time of the keel laying ceremony in December 2014: “This vessel is evidence of Maersk Supply Service strengthening our position in the Sub Sea Support vessel market. We are very much looking forward to continuing the good cooperation with all involved parties to achieve delivery in February 2016.”

Damen Shipyards Galati in Romania was chosen for this project because it is well used to handling complex projects. The first-inclass DOC 8500 for Van Oord, which was delivered in December 2014, was also built in Galati. The construction timeframe was very tight, taking only 14 months and the shipyard still managed to deliver one week ahead of schedule. “For the most part the people from the dedicated team we had assembled for the first DOC 8500 are now working on the Maersk vessel,” said Remko.

Galati is able to achieve a reliable vessel of the highest offshore quality and in the agreed timeline, he adds. And indeed, it has a solid reputation for building specialist vessels and running several complex projects at the same time.